1. Technical Field
This invention relates to drain traps in plumbing systems that provide water seal between the drain and the sanitary sewer system.
2. Description of Prior Art
In prior art drain traps, a variety of different designs can be seen having capture and removal features within to prevent lost objects from passing through the trap into the draining system and beyond. These devices also provide a filter mechanism to remove clogs from the trap. See for example U.S. Pat. Nos. 1,817,376, 4,164,048, 4,179,762, 4,301,554, 4,949,406, 5,421,979 and 5,525,215.
In U.S. Pat. No. 1,817,376 a drain strainer is disclosed having a sliding tray removably positioned within the upper portion of the drain trap.
In U.S. Pat. No. 4,164,048, a combination sink trap access port filter device is disclosed having a U-shaped drain configuration with an extension element having a filter positioned within with an access opening.
In U.S. Pat. No. 4,179,762 a trap is illustrated having a cylindrical base portion with a filter disk positioned within.
U.S. Pat. No. 4,301,554 is directed to a drain trap having a removable tray inserted through one opening with a plurality of upstanding fingers to trap and drain material in the water flow.
In U.S. Pat. No. 4,949,406 a sink trap filter assembly is disclosed in which a filter insert is positioned in the vertical portion of a J-shape drain having an access opening and a filter basket within.
In U.S. Pat. No. 5,241,979 a structure of an elbow pipe device is disclosed in which an elbow pipe has a access port on its lower portion on which a threaded extension is positioned in which a filter screen is positioned.
Finally, in applicant's own U.S. Pat. No. 5,525,215 discloses an improved structure for a drain trap having a filter arranged within for visual inspection and cleaning with a flow through inspection reservoir insert and filter cap extending downstream therefrom.